


Four Kisses from Cú

by WhatTheDog



Category: Fate/Grand Order, Fate/stay night & Related Fandoms
Genre: Fluff, Friends to Lovers, M/M, New Year's Eve, New Year's Kiss, crackship, i think this technically qualifies, lots of kisses filled with purple prose
Language: English
Status: Completed
Published: 2019-01-20
Updated: 2019-01-20
Packaged: 2019-10-13 00:13:53
Rating: Not Rated
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 8,514
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17477630
Author URL: https://archiveofourown.org/users/WhatTheDog/pseuds/WhatTheDog
Summary: The challenge was simple: the first one to kiss all four Cús before midnight on New Year's Eve got to keep a magical blue gem. The only problem? Cú Alter.





	Four Kisses from Cú

**Author's Note:**

> This is pure fluff. I came up with the crackship of Diarmuid and Cú Alter, and after seeing no content, I decided to take it upon myself to create some. I missed writing this in time for New Year's, but eh. 
> 
> Anyway, I hope you enjoy Diarmuid's quest to smooch every single version of Cú Chulainn.
> 
> Note: I don't actually play Fate/Grand Order, but I like it, so I apologize for any OOC behavior or any stuff that's incorrect.

“Slow down!”

Diarmuid ignored Nero’s cry. Ahead of him, Robin Hood raced through the forest, dodging around trees and leaping over roots as if it was second nature. It probably was.

“Guys!”

There was no time to stop. Daylight was fading. They needed to complete the mission and get back to the checkpoint to rayshift.

“Diarmuid, Robin, you can slow down a little. I promise we will still get there.”

At Mash’s order, Diarmuid reluctantly slowed down, Robin as well. It was best to listen to the Team Leader. Master always wanted a report on unsupervised missions, and it was in anyone’s interest to get a glowing review. Especially for Diarmuid. He almost never got picked to go anywhere.

He and Robin turned around as Mash strolled up to them. Behind her, Nero huffed and puffed.

“Why do you guys always run like you’re being chased?” she whined.

“It’s not our fault you chose to wear heels in a forest,” Robin pointed out.

This earned him a glare.

Mash disregarded the bickering and scanned the clearing they’d stopped in. “I think we’re close. Roman said the disturbance was 800 meters from our starting point.”

“Perfect." Robin hoisted his bow. "I’ll get us some tree cover, so we can ambush whatever it is.”

Diarmuid shook his head. “There’s no honor in sneak attacks. We should challenge them to a fair fight, like any other opponent.”

A snort echoed through the clearing, Robin already rocketing up into the overhead canopy. “What nonsense. No wonder Master rarely chooses you with crap ideas like that.”

Diarmuid grit his teeth. Bold words. Robin was lucky he was in a tree.

“Will all of you stop acting like children?” Mash said, crossing her arms.

“Yeah, you guys are—”

A shrill scream cut Nero off as a black blur came flying toward them. Diarmuid raised his spears, but he wasn’t as fast as her. In less than a blink of an eye, her red blade sliced the offending creature in half.

“Well, that was easy.” She rested one arm on her hilt, the tip planted in the ground. “Now where are the others?”

“I… I think that was it.” Mash looked slightly dumbfounded. “I don’t sense anything anymore.”

She was right. The forest seemed calmer now that the black thing lay in two, oozing a dark, congealed substance.

“Are you kidding me?” Nero cried. “I just wasted my day. I could have stayed home!”

As she continued to rant, Robin gracefully leaped from branch to branch on a downward trajectory.

Diarmuid watched him and smirked, twirling a spear. “Thanks for the tree cover,” he hollered. “Don’t know what we would have done without you.”

In retaliation, the archer jumped off his current branch… right toward Diarmuid.

He jerked back, attempting to sidestep, only to fall ass over teakettle on an upturned tree root. Heat rushed into his cheeks, but the nearby giggles made him wish for invisibility. 

“Smooth,” Robin quipped. He dusted himself off, annoyingly unfettered by the move.

Diarmuid grunted and pushed himself to his feet. Something dug into the palm of his hand, and he glanced down.

A beautiful, heart-shaped blue gem sparkled in the dim forest light.

“Wow, what is that?” Mash rushed over, peering at the gemstone. “Was the creature carrying this?”

“If so, it’s mine!” Nero pushed her aside. “I’m the one who killed it.”

“As Team Leader, I get first dibs on any loot,” Mash said. “This gem has a strange kind of aura. I bet it has some magical properties that would strengthen my shield.”

“Okay, but have you considered that you did literally nothing?”

“Ahem.” Robin stepped forward. “But we don’t know if that came from the creature. So… since the whole reason it got discovered was because I jumped toward Diarmuid… I say it’s mine.”

Diarmuid glared at him. “I’m the one who found it! All of you are coming up with these ridiculous reasons when I’m the most legitimate owner.” He glanced back down.

Mash was right about the magical aura. The gem radiated a strange kind of power. While he wouldn’t have much use for it himself, if he gave it to Master… she might remember it and choose him more often. It was worth a shot.

Nero scoffed. “What would you even do with it? I would at least have a use.” She smiled down at her décolletage. “It would make an excellent brooch.”

“Figures you’d only think about yourself,” Robin muttered.

“Oh? And what would you use it for?”

“To give to the poor.”

“Are you serious—”

“Everyone!” Mash interrupted. “Since none of us can agree on who gets it, I say we just give it to Master.”

Nero waved her arms. “Time out, time out.” She smiled at Mash. “I understand where you’re coming from… but I think I have a better idea.” She flounced over to Diarmuid, then stopped, hands on her hips as she faced the rest of them. “I propose a challenge. Some way for us to compete for this beauty.” She plucked the gemstone from the ground and held it up, letting it sparkle in a brilliant array. “You know what the color reminds me of?”

“The ocean?” Robin guessed.

“The sky?” came Mash’s answer.

Diarmuid didn’t respond. He just narrowed his eyes at the grinning Nero.

“Nope.” She grinned wider. “How about… Cú’s hair!” At the befuddled glances, she raised a finger. “I’m getting there. Since this reminds me of Cú’s hair, and the heart reminds me of romance… my proposed challenge is that the first person to kiss all four Cús will get to keep the gem.”

Robin scoffed, Diarmuid frowned, and Mash blanched.

She shook her head. “Cú is like my uncle. I couldn’t do that!”

“Well, not you then. You’re only sixteen, anyway.” Nero cleared her throat. “Here’s the deal. There’s exactly one month until New Year’s. Me, Robin, and Diarmuid will have until midnight of New Year’s Eve to kiss the four Cús on the lips. No tackling them or pretending to pass out so you get mouth-to-mouth. They have to do it willingly.” She glanced at Mash again. “If none of us complete this task in the allotted amount of time, then you get the gem.”

Mash nodded. “Okay.”

“That’s not fair.” Robin pursed his lips. “You’ve basically guaranteed she’ll win. None of us are ever going to get Cú Alter to kiss us.”

“That’s why it’s a challenge, dummy.” Nero smirked. “You telling me you’re afraid of a little challenge?”

“No. I’m annoyed at being given an impossible task.”

“That’s why,” she sang, casting a smile at Mash, “you can sabotage any of us for any of the Cús EXCEPT for Alter. You leave us alone with him.” She pivoted to Diarmuid. “What do you say?”

He shrugged. “Sure, whatever.”

“I’m down with that,” Mash chimed in.

Nero fluttered her eyelashes at Robin. “So?”

He shot her an ugly look. “Fine. I’m in.”

* * *

They gave the gem to Da Vinci for safekeeping upon arriving back in Chaldea. Without a moment to spare, Nero raced off, with Mash close behind. Robin bade goodbye to Diarmuid, and he walked back to his quarters deep in contemplation.

Truthfully, he didn’t feel optimistic about his chances. Lancer, Caster, and Proto would all be easy enough, but Alter? Robin had a point. You were more likely to get bitten than kissed.

He sighed. Why bother? He had charm, but he wasn’t as flirtatious as Nero. Nor was he as conniving as Robin. He might as well just accept that the gem was gone forever.

He went about his life as usual for the next few days. Occasionally, he saw Lancer Cú or Caster Cú and would start to approach, but that was always before he would catch the sight of a frowning Mash shaking her head. He got the hint.

He only grew more dejected when Nero taunted him, giggling, “I’ve already kissed both Lancer and Caster. You better get a move on.”

Great. Already in last place. He should just forgot about the whole thing. It was easier to swallow defeat when he was expecting it.

With his ambitions gone, he headed to rayshift. If he could go somewhere with a nice forest, he could take a walk. Cheer up. Take his mind off the challenge.

“Hey, Diarmuid! Wait!”

He glanced behind him, and his mouth nearly fell open.

“Are you going to a forest? Some place with trees? Anything?” asked Caster Cú, struggling to run in his flowing get-up. “I have to get out of here.”

Diarmuid nodded, trying to appear nonchalant. “Y-yeah. That was the plan.”

“Cool. You okay if I bum a ride?”

Again, he nodded. Before long, they were walking through dense vegetation, cast in a green glow. Diarmuid kept his eyes trained on the sun-dappled ground while Cú licked random trees, then announced their flavors. A little bit of an odd activity, but not out of the ordinary for him. At least there hadn’t been any ill effects so far.

“Damn, so Mash has been practically hounding me,” Cú said. He licked another tree. “Mmm, kind of spicy. Anyway, it’s just been a little weird. I like hanging out with her, but she’s acting like a guard dog for some reason.” He snorted. “Or maybe I’m imagining things. Who knows.” He paused to lick yet another tree. “Yuck, that one was bitter.”

Diarmuid kicked a pebble, frowning at Cú’s stream of consciousness. Even though he could explain Mash’s behavior, he didn’t know if he was allowed. It would probably be cheating to tell Cú about the challenge. Better to keep him in the dark. They could all laugh about it once New Year’s hit.

“Hey, look at that!”

Diarmuid jerked his head at the shout. Spinning to face Cú, he followed the pointed finger to a plant growing on the side of a tree.

“It’s mistletoe!” Cú grinned wolfishly. “Too bad we aren’t standing underneath it, huh?”

Like chilled water, a strange epiphany seized Diarmuid. His head finally broke the surface of premature defeat, where Caster Cú stood, single eyebrow quirked, as his savior from drowning in loss. The words bubbled out, faint, yet more confident than he felt. “Since when has that ever stopped you?”

Cú grinned wider. “Good point. You want to?”

Diarmuid answered by crossing the gap between them. With one fell swoop, he connected their lips.

It tasted almost minty, with a bitter undertone, perhaps from the dozens of trees Cú had already indulged. His lips were smooth and warm, slightly dry, but pleasing to the senses. Diarmuid let the kiss wash over him, surprisingly chaste considering his companion. Only the fingers running through his hair alerted him to any hint of desire.

When they separated, Diarmuid’s expression reflected Cú’s—a shit-eating grin.

First one down, baby. He was back in the game.

* * *

In any competition, strategy was essential. It was important to know your enemies’ tactics and to figure out the best of course of action to win.

The problem was Diarmuid had no clue where to go after Caster.

Should he pursue Lancer? Proto? Maybe even try his chances with Alter?

He approached Robin to see how far he was.

“I’ve kissed Lancer and Proto so far.” Robin shrugged. “Nero has me beat, though. She’s kissed everyone except for Alter.”

Damn. So he was still in last place. The good feeling from his walk with Caster Cú fizzled before he told himself to snap out of it. No time for negativity. Only time for winning.

He found Proto Cú in one of the lounges, digging under a couch. All right. This was promising.

“What are you looking for?” he asked.

Cú grunted. “I had some cinnamon gum and now I can’t find it. I’m sure it’s somewhere in this room.”

Diarmuid bent down to help him look. Was it behind the big couch? Nope. Under the loveseat? Zip. Behind the potted plant? Yes! Bingo!

Cú practically leapt for joy. “Dude, you’re the best! Thanks!” He shoved another stick in his mouth, chewing noisily. “Want some?”

Diarmuid shook his head. “No, I’m fine.” An idea wormed its way in, and he tried to lean against the adjacent wall casually. “But I wouldn’t mind a different kind of reward.”

His bravado crumbled as Cú gave him an odd look. “What do you mean?”

“Uh… you know, perhaps a… kiss?” He cringed. Now that the words had escaped, it sounded pretty sleazy. Much sleazier than in his mind. The disbelief on Cú’s face only made everything worse.

“What’s gotten into everyone?” he muttered.

“If you don’t want to, it’s fine!” Diarmuid blurted. “You’re chewing gum, and it’s not as if I really did that much and—”

Cú pressed a finger against his lips. “How about you stop rambling, or else I’m not going to take out my gum.”

That shut him up. He watched Cú put the sticky blob into a wrapper, then fold it up.

Scrunching up his face, Cú leaned forward, quickly pecking Diarmuid’s mouth. Even though it was brief, the sting of cinnamon pervaded the kiss, more of a bite than the small nip Cú performed as he pulled back. He brushed his stray fringe from his face, then departed the room, the fresh smell of cinnamon wafting out as he left.

Diarmuid stared at the floor. Took a deep breath. Two down. He was halfway there.

* * *

Lancer and Alter. That’s all that was left. Not much, but the month was halfway over. He needed to get a move on.

Diarmuid set Lancer as his next target. They were pretty familiar with one another, and it wouldn’t seem too weird to talk to him about sparring. They hung out all the time.

Like he’d predicted, he found Lancer Cú in the training room, practicing some spear tricks.

“Hey,” he called out, receiving a friendly “ _Yo!_ ” in return. “Interested in a sparring match?”

Cú hefted his spear, propping it on one shoulder. “Fuck yeah, dude.”

They faced each other, sizing one another up, muscles tensed and ready. Cú made the first move. He lunged forward, a quick jab that Diarmuid parried. His counter failed, and Cú stabbed again, only to be parried once more. Neither gained any ground. Stab, thrust, parry, stab, thrust, parry, again and again. Occasionally a slash or a slice for variation.

After several minutes, Diarmuid called a time-out. “Want to spice things up?” He grinned as Cú raised an eyebrow in amused puzzlement. “We could set some stakes for the match.”

“Like what?” Cú asked, and Diarmuid wanted to laugh at the barely contained enthusiasm. Apparently, he wanted things to be a bit more interesting, too.

“Well, let’s say that the winner of the match gets a reward. If you win, I have to pay for your lunch somewhere.”

Cú smirked. “While I know that I’ll win, I’m still curious… what would you get in the unlikely scenario that you win?”

Through half-lidded eyes, Diarmuid purred, “A kiss.”

“Hey, guys!” a bubbly voice yelled out. “Mind if I watch?”

Diarmuid’s heart sank. Mash! Why was she here? There was no way he’d get to kiss Cú if she were present.

“Yeah, that’s fine,” Cú responded nonchalantly. “Diarmuid has some weird stakes, but it won’t matter, since I’m going to destroy him.”

“Good luck!” Mash cheered.

Diarmuid grit his teeth, shifting his weight into a better starting stance. No more playing around. He couldn’t screw this up.

Like before, Cú attacked first. Diarmuid deflected the blow, then tried to feign to one side. Hopefully, Cú would take the bait.

It worked, and he used his other spear to strike his target’s opposite side. Cú was too fast though, and their fierce dance resumed.

With each step, Diarmuid’s mind raced. What could he do to ensure victory? He was skilled, but his stamina was waning. Two spears took a lot of endurance, and Cú was slowly but surely pushing him back.

Time to get aggressive. He pretended to stumble, shifting his weight, his grip tightened on Gáe Dearg. Cú lunged forward, spear sweeping down in an arc. Diarmuid deflected, then went in for the kill. He rushed right into Cú’s space, long spear angled low, too low for Cú to block.

The flash caught him off guard. He stumbled, this time for real, before pain seared through his right shoulder. Another sweep knocked him off his feet, and it took a moment for his eyes to focus on a triumphant Cú.

“That was a great picture!” Mash shouted from the sidelines. “Sorry you got distracted by the flash, Diarmuid.”

Of course. She couldn’t let him win. Bitter disappointment coated his tongue, even as Cú helped him up.

“That was kind of lousy she did that,” Cú whispered. He glanced backward, and a toothy grin erupted on his face. “You know, just because you did such a great job…”

He cupped Diarmuid’s face and pressed their lips together. Diarmuid sank into the kiss, tangier than Caster’s or Proto’s. More aggressive, too. He allowed Lancer access to his mouth, the talented tongue creeping forward, just enough to tantalize, then drawing back for the actual attack. When it retreated for the final time, he leaned closer, eager to savor every delicious second on his palate.

They broke apart, panting, cheeks tinged with color. “You still owe me lunch,” Cú said with a wink.

Diarmuid nodded, then couldn’t help but cast a sly grin at Mash.

Boy, she was pissed.

* * *

He had to do something about Alter. It had gotten to that point.

There were only a couple days left in December, and he was no closer to approaching the intimidating berserker. Sometimes he’d meekly wave at him as they crossed paths, but he hadn’t worked up the courage for a conversation. Much less a kiss.

Things only seemed more bleak when Master picked Cú Alter for a supplies mission. Now he’d never complete the challenge. He’d have to spend the final days of the year moping about a dumb gem.

It came as a complete shock when Master asked him to come along.

“Me? Really?”

“Yeah.” Master smiled warmly at him. “Nero insisted that you and Robin Hood join me, Cú, and Mash. I think we’ll make a good team; there’s a nice variety of classes.”

Okay, that was odd. Why would Nero insist on his and Robin’s behalf?

He followed Master to rayshift, where Roman and the four other Servants waited. Robin and Mash appeared just as baffled as he felt, while Nero flashed a cheery smile. Cú Alter stood off to the side, ignoring all of them.

As Roman debriefed them, Diarmuid leaned into Nero’s ear and whispered, “Why did you want us coming along?”

Robin joined in as well. “Yeah, you would have had Cú all to yourself. What gives?”

Nero maintained her glowing expression. “We’re all tied, are we not? Haven’t both of you kissed the three other Cús?”

He and Robin nodded.

“Well,” she hummed, eyes sparkling, “this gives all of us even ground. Therefore, when I win, my victory will be all the sweeter.”

Diarmuid frowned, with Robin scoffing beside him. She really was a piece of work.

“Will you guys quit talking about your stupid challenge?” Mash muttered.

Robin shot her a look. “What’s gotten into you?”

“Oh, she’s just mad that she can’t do anything to sabotage any of us.” Nero nudged Mash, winking. “Isn’t that right, sweetie?”

If looks could kill, Nero would have been vaporized.

“All set!” Roman announced, and they took their places.

A few moments later, they were traipsing through some sort of tropical rainforest, following the determined form of their Master.

“We’re heading into some caverns, so hope everybody has been eating their carrots!” Master said. She laughed at her own joke, and everyone besides Cú gave a few half-hearted chuckles.

True to her word, the caverns soon swallowed them in shadow. As they progressed deeper in, all light faded, and only after a few minutes of fumbling did they manage to activate any kind of illumination. Master passed out glow sticks, and Diarmuid enjoyed hanging the colorful fluorescence around his neck.

The first fight started not long after. He and Robin stayed in the rear as back-up, observing their fellow Servants take out a few skeletons. So far, looked to be a pretty easy skirmish.

“Everybody, let’s collect the loot!” Master ordered.

All of them scavenged the remains, picking out any valuable objects and returning them to her in exchange for exclamations of praise.

Nero used the opportunity to try to cuddle up to an indifferent Cú. “You were so sexy back there. Didn’t even break a sweat.”

He shrugged her off, and Diarmuid rolled his eyes at her antics. Off to the side, Mash gripped her shield so tightly her knuckles turned white.

The second fight was a bit tougher, but Mash did her best to protect everyone, even though Nero took a few hits. Diarmuid smirked to himself; hard to believe  _that_  would happen.

When the fight ended, they again collected the loot. This time, Robin was the one to extol praises on Cú.

“Man, I can’t believe how hard you hit," he said, admiring Cú's biceps. “And for a berserker, you’re still a tank. My arrows wouldn’t do anything to you, even if you didn’t have Protection from Arrows.”

Like before, Cú ignored the compliments as Mash glared.

Deeper in they traveled, searching for more enemies. Robin was the first to spot any. “Over there!”

“Alright!” Master took her usual stance, signaling to the rest of them. “Looks like some kind of wraith. Cú, you should use your Noble Phantasm. I want to take that thing out in one hit.”

Without a word, he rushed forward, activating Curruid Coinchenn. Red spears sliced through the wraith, splattering ectoplasm left and right, even carving gouges in the walls.

Diarmuid couldn’t help but wince. Damn, he was _really_ glad Cú was on his side.

“Collect the loot!” Master chirped once the battle finished. Once more, they rooted around in the gooey remains, a few disgusted groans sounding here and there.

Diarmuid gathered up a page, shaking some ectoplasm from it. As he straightened, he paused. Tilted his head. What was that sound? He tensed. Sounded kind of like… rumbling?

“Everybody, got all the stuff?”

Everyone started an affirmative when all hell broke loose. CRASH! The faint rumbling announced its full presence with a roar. Rocks tumbled down on them, and Diarmuid leaped out of the way. Dirt and dust choked him, but he covered his head, wincing as the cacophony wore out its welcome.

When he raised it, his breath caught in his throat. Somehow he’d lost his glow stick, and he’d been plunged into an inky blackness.

“Everybody okay?” came Master’s faint voice. A chorus of muffled agreement met her question.

Diarmuid opened his mouth, but coughed on the residual dust. He staggered forward, only to bump into an impenetrable barrier of fallen limestone. Oh shit. He frantically dug his fingers in, searching for any crevices, any cracks that he might fit through.

“Diarmuid, Cú, I haven’t heard from either of you.”

“I’m okay,” he called out.

“I, too, am unhurt.”

He nearly jumped out of his skin at Cú’s sudden presence. There was a spark, and then a floating orb of light bathed the area in a pale glow. Runes. Thank Lugh.

Cú looked nonplussed. “Master, it appears we have been separated from you and the others.” He hoisted up a bag. “I also appear to have most of our loot.”

“Oh crap. Can you destroy the rubble in the way?”

“That may cause another rockslide, but we have other options.” He glanced behind him. “From what Roman said during the mission debriefing, there should be another exit besides the entrance we used. If you and the others leave the caverns, we can all meet up outside that point to rayshift.”

“Uh… okay. Just… be careful, you guys. I don’t know what else is in here. There’s a high likelihood there might be more enemies, and I won’t be able to revive you.”

“We’ll manage.” Cú immediately strode away. “We should get a move on. Diarmuid, come.”

Composing himself, Diarmuid hurried after the hulking form. What in the hell was all of this? This wasn’t supposed to be a difficult mission. Yet here he was, stuck in some random cavern with Cú Alter.

Cú Alter and nobody else. Realization dawned on him. This could be his chance. Who knew how long it would take them to reach the exit? He had plenty of time to chat up his target, and maybe even steal a kiss. This was perfect!

“Wow, you were awesome back there,” he said, struggling to keep up with Cú’s pace. “That wraith didn’t stand a chance!”

Cú didn’t even turn his head, but merely grunted.

Diarmuid scrambled to find more to say. “Uh… it’s just… pretty cool that you’re so strong you can decimate an entire cavern. I know plenty of anti-army Noble Phantasms that can do that, but to see an anti-unit one accomplish the same re—”

“I’m going to be blunt here.” Cú stopped abruptly, and Diarmuid had to duck to avoid the thrash of his tail. “I’m not going to kiss you.”

It took a moment for Diarmuid to collect his jaw from the floor. “Excuse me, but…  _what?_ ”

“I’m not stupid.”

Cú finally turned toward him, the pale glow from his rune orb draining his skin of color, yet highlighting the crimson of his eyes and facial tattoos. He looked more feral than inviting, and a prickle of unease actually crawled down Diarmuid’s neck.

“Contrary to what many believe, I sometimes do interact with the other versions of myself, and thought it very interesting that Nero, Robin Hood, and you all seemed so intent on kissing them. When the three of you just happened to be on this mission, all so complimentary, fawning over my every move, I put two and two together. I don’t know what your bizarre challenge is about, but I have no desire to indulge any of you.” He faced away. “Now, shut up and keep walking.”

The echoes of their footfalls rang hollow in Diarmuid’s ears. It was over. Truly over. He had no hope of winning. What a disappointing month. So much anticipation only to get crushed in the end. To top it off, now he had to endure an awkward trek with Cú Alter.

Then again… was it really any more awkward than him unsuccessfully attempting to flirt? He didn’t have to schmooze anymore. He could treat Cú like anyone else. The weight started to lift from his shoulders. This was okay. Yes, it was frustrating not to get the gem, but he didn’t need it, anyway. If he did well on this mission, it could accomplish the same result.

He found himself smiling inadvertently. “You know,” he started, chuckling, “I’m… I’m actually really glad you said something. I’ve been apprehensive at the thought of kissing you, and it’s… nice not to worry about it anymore.”

Cú didn’t respond.

He laughed nervously. “If you’re curious, the winner of the challenge would have gotten a magical blue gem. The rules were that we had to kiss every version of you before midnight on New Year’s Eve.”

“What use would you have had for such an object?” Cú still didn’t look at him, his eyes trained on the never-ending expanse of cavern. “You have a subpar mana stat if I recall.”

“Well… yes.” Diarmuid fiddled with a spear. “But I didn’t want it for me. I wanted it so I could give it to Master, as a gift. Something to remind her of me.” Heat rushed into his cheeks as he mumbled out the next part of his rationale. “So, then maybe she would… pick me more often.”

Cú’s voice was flat. “I doubt that would have influenced anything. You need more than a pretty rock to outweigh shortcomings.”

Oof. That… that stung more than he cared to admit. He swallowed a rebuttal. He would just look thin-skinned if he tried to argue his utility. Better to stay quiet.

The air grew colder as they continued to walk. Diarmuid tried to hide his shivers, wishing for longer sleeves, even the heat of the outside rainforest. He glanced at Cú’s cloak, embroidered with that fluffy, red fringe. Man, that looked comfy. He wished he had something like it.

A long, piercing scream echoed off the cavern walls, originating ahead of them. He stiffened, spears at the ready, while Cú also adopted a fighting stance. The whoosh of air grew louder with each second, and a strange bat-like creature came soaring toward them, teeth bared.

Diarmuid pulled his arm back, aiming his spear like a javelin. Cú beat him to it, though. Red energy coursed through the cavern as Gáe Bolg seared forward, obliterating the creature instantly.

Lowering his arm, Diarmuid contemplated the unrecognizable corpse. Cú was right. No wonder Master never picked him; he couldn’t accomplish anything like that. Still, he might as well show gratitude.

“Thanks for getting that—OH LUGH!” He gaped at Cú.

His right arm dangled at his side, barely connected by a few strands of sinew and bone. Blood bubbled and flowed onto the cavern floor, the ghostly light painting it a too-bright red, sickly and garish. Cú’s face was twisted in agony, but he made no sound. With a few quick gestures of his good arm, he created several runes that healed the appendage back to its original condition.

“What…” Diarmuid had to shake his head, mind still reeling. “What was that?”

“Nothing.” Cú resumed his stride. “We should keep moving.”

“That didn’t look like nothing.” Diarmuid fell into step beside him. “Are… are you okay? How did that happen? You didn’t get attacked.”

He shrugged. “It’s simply a side-effect of throwing Gáe Bolg. I manage.”

“That looked horrifically painful.”

“Like I said, I manage.”

Diarmuid opened his mouth to protest, but the tone was clear. The conversation was over. He nodded, still perturbed, and cast his gaze back toward the maw of darkness gaping before them.

Only a few minutes after their first encounter, another bat creature shrieked out a greeting. It came barreling toward them, and Cú once again hoisted Gáe Bolg.

Everything seemed to slow down. Diarmuid watched the wind-up, muscles contracting in preparation for the launch. Bile rose in his throat, the mangled limb assaulting his mind’s eye. He couldn’t let that happen. Not this time. Nobody, not even Cú, could handle that much pain.

Without even thinking, he sprang forward. A brief wave of panic washed over him as the creature filled his entire field of vision. He ignored Cú’s angry shout from behind, and drove his spear into the furry chest. Gritting his teeth, he weathered the sharp claws digging into his shoulder, twisting the spear deeper.

It took a moment for him to realize his enemy was dead. Dark liquid gurgled out from its mouth, and it went limp. He took a step back, dazed. That hadn’t been like him. He wasn’t an impulsive fighter.

“Why did you do that?” Cú snarled. He rushed forward, glare more deadly than either of Diarmuid’s spears. “I could have hit you.”

“Well, you didn’t, so no harm done,” he replied, trying to hide the scratches in his shoulder. “We should keep walking.”

Cú narrowed his eyes but didn’t argue.

On and on they went, the distant drip of water their only companion. When yet another bat creature attacked, Diarmuid lunged forward like before, tackling the creature to the ground. They had a brief wrestle, and he killed it with a slash. He repeated this for the next two encounters as well, his injuries growing along with his fatigue.

After their sixth encounter, Cú finally snapped.

“Will you stop that?” He grabbed Diarmuid roughly, examining the crisscross of bites and scratches covering his upper body. “All you’re doing is getting hurt when I could take them out in one hit.”

“I’m okay.” Diarmuid tried to sound confident, but he couldn’t meet Cú’s steely gaze.

“Maybe you are now, but soon you’ll be nothing but dead weight. Just get out of the way and stop pretending to be useful.”

Diarmuid whipped his head back to face Cú. The word rattled throughout his skull. _Useful_. All trepidation was gone as he straightened to his full height.

“What’s it matter whether I'm dead weight or dead?” he spat. “You’re the more valuable Servant. Master won’t care if I don’t come back.” He stood his ground even as Cú’s nostrils flared. “If you really want to know, I was trying to stop you from throwing your spear. I know I’m not strong, but me getting beat up is better than you destroying yourself.” He turned away, shaking from anger. “I’m not pretending to be anything. I’m just trying to help you out.”

“What a stupid reason.” Cú released him and continued into the caverns.

Diarmuid clenched a fist. The words came out before he could stop himself. “Believe it or not, caring about other people isn’t stupid. You should try it sometime.”

Cú looked over his shoulder. His eyes were blank, cold. Diarmuid stared into their stony depths, trying to maintain his resolve.

“Your agility is your best stat,” Cú finally said. “Rushing into a fight doesn’t suit your style of combat. You’re better at strategy and evasion, making your enemies come to you. Play to your strengths, and I won’t throw Gáe Bolg anymore.”

Diarmuid blinked as Cú turned back around. Wow, that was… unexpected. An involuntary smile formed, and he hurried after his companion, his spears suddenly much lighter. He’d actually reached Cú Alter. That was a victory on any day.

He heeded Cú’s words at the next attack. There were two bat creatures instead of one, and he let Cú charge forward to take out the first, while he stayed back. When the second bat came within striking distance, he finished it off with a few quick thrusts of Gáe Dearg.

Cú gave an approving nod as the battle finished. Diarmuid grinned and followed after him.

A few hours and several enemies later, they decided to call it a night. Cú flopped down on the ground and used a rock as a pillow while Diarmuid settled down a few feet away, resting his head on his arms. It wasn’t very comfortable. He shivered, trying to curl up and conserve body heat. Not great odds for any kind of rest.

He tossed and turned the whole time. The cold ground sapped him of warmth, and his trembling gradually converted into full-blown teeth-chattering tremors. He wrapped his arms around himself tighter. Just bear it. Cú would hopefully wake up soon.

Surprise washed over him when a fuzzy softness enveloped him. He didn’t raise his head, but he cracked an eye open to see that Cú had placed his cloak on his back. The berserker had already returned to his own spot.

Diarmuid pulled the cloak tighter, burying his face into the red fluff. Blood and iron assaulted his nose, but some other fragrance lingered beneath the carnage. A subtle sweetness with a bit of spice to it. He smiled and let Cú’s scent lull him to sleep.

* * *

When he woke up, he found the cloak gone. As he stretched, Cú greeted him with a nod, and soon they resumed their journey.

Diarmuid absentmindedly twirled Gáe Buidhe as they walked, an odd mustard color in the glow of the orb. Everything was so unsaturated in this light. He redirected his gaze to his companion. Even the ebony of Cú’s outfit seemed washed out, paler than the impenetrable blackness before them.

He coughed. Might as well strike up a conversation. “So, what kind of stuff do you like to do?”

“Irrelevant.”

“Uh…” He scratched his head. “Okay. What about stuff you don’t like?”

“Doesn’t matter.”

“Huh. Didn’t really picture you as an easygoing guy.” He straightened. “You must have something you like or don’t like. What about food?”

“I don’t eat.”

“Oh.” Diarmuid paused, frowning. “That’s a shame. Food in the modern era is so good.” He laughed awkwardly. “For example, french fries. I about lost my mind the first time I ate any. And fried chicken? Wow.”

Cú glanced over at him, expression unreadable.

He continued, “When we get back to Chaldea, you should try some french fries. Maybe you’ll like them.”

“I doubt it.”

“Well…” He struggled to fill the silence. “You never know. I'm… I’m finding it hard to believe that you’ve never eaten anything. Are you sure? Not a single thing?”

Cú didn’t respond for the longest time. Finally, he shrugged. “Master once persuaded me to try a bite of black forest cake. It wasn’t horrible.”

Diarmuid couldn’t help but grin. “Oh, that stuff. Chocolate with cherry, right?”

“I don’t know what’s in it.”

“That’s okay.” He smiled to himself. “I don’t eat dessert too often, but I do like sweets. Grainne used to make these honey oat cakes back in Ireland. She would always tease me that I loved them more than her, and I’d laugh it off.” He fidgeted. “But I always felt kind of guilty because there was a kernel of truth to it, what with the geas and… yeah.”

He stopped talking, instead letting out a quiet breath. Wow. He hadn’t meant to bring up something so personal.

“Geases are unfortunate things.”

The words caught him by surprise, and he turned to see Cú staring ahead with a hollow gaze.

He nodded, choosing to remain quiet. Nothing needed to be said.

A few minutes later, the air grew less musty. Diarmuid sucked in a lungful. It felt… fresher. There was even a slight breeze. “We must be nearing the exit.”

“Yes.” Cú gripped his spear tighter. “And something else.”

He was right. An odd clicking noise filled the air. Diarmuid readied himself as a faint scuttling crept closer. They inched forward, straining for any detection of movement.

Something wet dripped onto Diarmuid’s shoulder. He wiped it off, examining it. Some sticky, clear substance. He glanced upward.

And nearly screamed.

Eight, enormous eyes peered down at him, framed by thick bristles with razor-sharp fangs underneath. The massive spider aimed its spinneret at Cú.

“Cú!” Diarmuid shouted, but it was too late.

White string shot out, covering him within seconds. He snarled, tearing strands left and right, but his movements were sluggish. Unnaturally so.

Diarmuid hurled Gáe Buidhe at the spider, only for it to bounce off the abdomen. Descending onto the cavern floor, the spider scuttled toward Cú.

Diarmuid rushed toward them. He leaped on top of the spider, ignoring the click of its chelicerae as it bucked like a wild bull. Clutching some bristles, he tried to jab Gáe Dearg into the back, but it wouldn’t penetrate. A particularly vicious flail sent him flying to the side, where he pushed himself to his feet.

The spider bore down on Cú when a flash of red stopped the attack. Lodged in-between the two combatants, Gáe Bolg held the fangs at bay, and the spider could only spit viscous saliva in retaliation.

Again, Diarmuid lunged forward. A black blur knocked him flat on his back, and he wheezed, rubbing stars from his eyes. Why had Cú struck him with his tail?

“Get out of here!” Cú hurled the bag of loot to Diarmuid’s side. “I’ll fight this thing off. You get the supplies back to Master. We can’t afford to lose them.”

The bag felt strangely heavy as he picked it up. Per Cú’s order, he started a loping run in the direction of the exit, but the hiss of more string made him stop. He turned around, taking in the sight of Cú grappling with the giant arachnid, who had redirected its spinneret toward the berserker.

His speed and strength were off. Almost like the string was sapping it out of him. Meanwhile, the spider’s jerks and flails seemed far more violent than when Diarmuid had straddled it.

A cold rush descended over him. There was some strange magical property to that string; some ability to drain an enemy of their prowess and redirect it to the spider. If he left, there was a chance that Cú might not make it to the exit.

He dropped the bag on the ground. As he raced forward, he lifted Gáe Dearg, eyes locked on his target.

A blob of string pulsed toward him, but he dodged to the side. Drawing his arm back, he activated his Noble Phantasm, then drove the spear right into the spinneret’s main hole.

The spider thrashed. Milky fluid poured out, forming a puddle at Diarmuid’s feet. With a few slashes, he freed Cú from the remaining embrace of string, but he wasn’t watching behind him.

Agony tore through his midsection as he was lifted from the floor. He struggled, gasping, the pedipalps clamped around his waist, where fangs burrowed in, spilling dark blood. His blood.

He closed his eyes. This was it. Master wasn’t here to revive him. He was going to perish in the jaws of a spider in some dark cavern, but at least he had saved Cú. That was something. He would complete the mission.

A low growl echoed off the walls: “Slaughter without exception. Liberate all curses without moderation. Be prepared to challenge despair.”

Diarmuid opened his eyes right as Cú roared “ _Curruid Coinchenn!_ ” and a blaze of red enveloped everything in sight.

The world spun upside down, and the ground rushed up to meet him. He slammed into it, hard, coughing as a high-pitched squeal assaulted his ears. Warm, wet globs of tissue and harder exoskeleton pelted his body, and he covered his face as the spider disintegrated all around him.

“Can you stand?”

Diarmuid didn’t immediately register the question. He gazed blearily up at Cú, no longer wielding huge claws and a red-horned helmet. No, it was regular Cú Alter, bathed in the orb’s white light, illuminating the wine red of his eyes and the deep blue of his hair. Terrifying and beautiful, all at the same time.

“I said, can you stand?”

He snapped to attention. “I… I can try.” He staggered to his feet, and the surge of pain through his stomach nearly made him double over.

Cú caught him before he collapsed back to the ground. “I told you to escape.”

Diarmuid struggled to speak, slurring his words. “I couldn’t… spider was magical. Bad. Very bad.”

“I’m aware. Although I guess I can’t fault you for your decision. Master would have been displeased if you returned without me.”

He blinked. Master? “I wasn’t thinking about her.” He grinned crookedly, Cú swimming in and out of focus. “I was thinking about how buddies help each other out.” He giggled, singing, “You’re my buddy.”

Cú sighed. “Great, now the venom’s reached your brain.”

He continued to giggle as Cú muttered a few words. A blue light settled over them, and the searing pain eased as the cavern stopped spinning.

Nausea suddenly seized Diarmuid as he bent over, vomiting out a strange viscous liquid. When he straightened, he groaned. “What just happened?”

“I used rune magic to heal you. That was your body’s method of eliminating the venom.”

He wiped his mouth. “You’d waste rune magic on me?” It could have been his imagination, but he thought he heard Cú chuckle.

“If you believe my choice to be a mistake, one of the spider’s fangs survived my attack. I could inject you with venom again.”

“No, no, no, I’m good!” He hopped to his feet and gave Cú a sheepish grin. “We can leave whenever.”

Cú nodded, plucking the bag of loot off the ground. “Get your spears, and we’ll head out.” He started toward the exit.

After Diarmuid collected his spears, he turned back toward the stationary Cú. "Hey... thanks for healing me." 

Cú murmured something inaudible.

“What?” He moved closer. “I didn’t hear you.”

“Diarmuid.”

“Yes, that’s my name.” He frowned. Cú looked almost pained. “What’s wrong?”

“Nothing.” Bowing his head, the berserker faced away from him. “Just… thank you for coming back for me.”

Diarmuid jerked, caught off guard, but he recovered quickly. “It’s no problem.” He jogged to Cú’s side and flashed a grin. "Like I said, we have to help each other out.” 

Cú replied with nothing but a nod.

Less than an hour later, they finally emerged into the muggy rainforest night.

“You guys are okay!” Master cried, rushing forward. “And you brought out the supplies. Awesome!”

Behind her stood Mash, Robin, and Nero. They all shot Diarmuid a questioning look, and he shook his head in reply. He had to bite back a laugh at the relief that bloomed across their faces.

Master looked through the bag, then faced all of them, beaming. “This is perfect. I was really afraid we were going to miss the New Year’s Eve party, but you guys were out just in time!”

The information hit Diarmuid like a ton of bricks. It was New Year’s Eve! He couldn’t believe a date he’d been so fixated on for an entire month managed to sneak up on him like this. Then again, he hadn’t really thought about the challenge for a while. He smiled to himself as their party prepared to rayshift.

When they returned to Chaldea, Master relieved them of their duties. “Enjoy the party, guys!”

“Oh, I definitely will.” Mash grinned and whispered, “Since I’m getting that gem and all.”

Nero glared at her. “There’s still a couple hours left,” she hissed. She glanced in the direction Cú Alter had gone and adjusted her neckline, pulling it down further than usual. “Watch a professional at work.” She hurried off.

Robin yawned. “Eh, whatever. I didn’t think I was going to win anyway.” He departed as well.

Diarmuid washed up in his quarters, then strolled into the main lounge, now decorated with streamers and an enormous banner reading, “ _Happy New Year!_ ” Several Servants greeted him enthusiastically, and he soon got caught up in the merriment of people playing “Whack-a-Saberface” while drunk karaoke serenaded their unfortunate ears.

A few minutes later, a terrified scream distracted them, and they turned toward the source of the commotion.

Diarmuid burst out laughing as a frantic Nero came streaking into the room, chased by a furious Cú Alter. Master admonished the berserker and relegated him to a corner. There, he glared at the other members of the party.

As the festivities wore on, Robin was the one who spilled the details of the challenge to the other Cús. They thought it was a riot, and Diarmuid had to duck as Lancer tried to whack him, while Caster practically rolled on the floor. Some of the Servants congratulated Mash, who excitedly prattled on about how she would use the gem.

Several cups of punch and a few rounds of drunk karaoke later, Diarmuid had all but forgotten about the challenge. Sure, he hated losing, but he could tell his competitive side to shut up. No, hanging out with friends was a lot more fun than pouting like Nero.

With only a few minutes left until midnight, he refilled his cup. He paused, thinking hard. Shaking his head, he filled another cup and headed off. He had a hunch someone else might enjoy it, too.

As he approached, Cú Alter gave him a suspicious look. He held up the cups in a plea of innocence.

“Just here to provide you with punch and company. No kissing, I swear.” He offered the beverage.

Cú still looked skeptical, but he nodded and accepted the cup. Taking a sniff, he wrinkled his nose.

“You said black forest cake wasn’t horrible,” Diarmuid pointed out. “Maybe this will also be ‘not horrible.’”

Cú frowned. Took a sip. “Fruity,” he said after a few seconds.

“Yes, it is. But what’s your verdict?”

Cú considered the cup for another few seconds. “Not horrible.”

Diarmuid beamed. “Glad to hear.” He took a sip of his own cup. “Got any New Year’s resolutions?”

This was met with a snort and rolled eyes. “I don’t do that sort of thing.”

“Too bad,” Diarmuid chirped. “I think it’s fun.”

Cú regarded him over the rim of his cup. “What’s yours?”

“To not be a sore loser and congratulate Mash on her gem.” He laughed. “I’m kidding. I was actually thinking about taking some combat classes. Improve my Arts attack. If I want Master to pick me more often, I need to play to my strengths.” He smiled. “Just like you said.”

Cú replied with nothing but a grunt and another sip of his punch.

Diarmuid checked out the large clock in the center of the room. He nudged Cú. “Psst, the countdown is about to start!”

After downing the rest of his punch, Cú tossed the cup. “I suppose it is.”

“Hell yeah!” Diarmuid cheered, feeling the effects of the drink. “We survived another year!”

The noise in the room dimmed as all the other Servants watched the seconds tick, then erupted when the clock drew to ten before midnight. “TEN, NINE…”

“EIGHT,” Diarmuid joined in. He nudged Cú again, who rolled his eyes once more. “SEVEN, SIX, FIVE, FOUR.” The punch took a spot on the floor as anticipation built. “THREE, TWO, ONE.” As midnight struck, he took a deep breath, then yelled “HAPPY NEW YEAR” along with all the other Servants.

He turned toward Cú, about to wish him in person, when he was swept off his feet and a mouth captured his own. All thoughts immediately left the premises.

In the past month, he’d kissed every single Cú. Caster had been short and sweet, like a flute of champagne; a light and bubbly experience, not enough for some, but pleasant still. Proto had been nothing but a small peck, an appetizer before dinner, a nip of potential. Then Lancer, who satiated any appetite with his fearlessness to engage, providing a main course of sensation and technique.

But Alter was not like any of them. No, this was the best treat of all, and if he had to compare this kiss to anything, it was dessert, as rich and intoxicating as the best wine, and warm enough to melt him like chocolate in all of its sheer, toe-curling decadence. He wrapped his arms around the broad shoulders as Cú embraced him, drinking him in, indulging him in honeyed excess. He greedily accepted all he had been offered, yielding to every caress of Cú’s tongue, bending to the whim of desire in all its mouthwatering glory.

They broke apart, and Diarmuid stood on his toes, desperate for one more taste. Cú relented briefly, sipping him like punch, then whispered in his ear, “Tell Mash I said congrats.”

And with that, he departed, leaving a blushing, starry-eyed Diarmuid in his wake.

Forget the stupid gem. He was the real winner.

**Author's Note:**

> Thanks for reading!


End file.
